Shock proof switch for clock delay mechanism



arch 1s, 195s E. H. BEACH V SHOCK PROOF SWITCH FOR CLOCK DELAY MECHANISM Filed Aug. 12,1952

4 Sheets-Sheet 1 INVENTOR EUGENE H. BEACH ATTRNEYS March 18, 1958 'E. H. BEACH 2,326,991

SHOCK PROOF SWITCH FOR CLOCK DELAY MECHANISM Filed Aug. 12, 1952 4 Sheets-Sheet 2 FIG.2.

. INVENTOR EUGENE BEACH ATTORNEYS Mar h 18, 19581: E. H. BEACH 2,826,9 1

.snocx PRoonswI'rcH FOR CLOCK DELAY MECHANISM Filed Aug. 12, 1952 4 Sheets-Sheet 3 Fig.3.

INVENTOR EUGENE H. BEACH ATTORNEYS Mmh 18, 1958 E. H. BEACH 2,826,991 'snqcx PRooF'swncH FOR CLOCK DELAY MECHANISM File'} Aug. 12. 1952 7 4 Sheets-Sheet 4 EUGENE H. BEACH" ATTORNEYS INVENTOR United States Patent O SHOCK PROOF SWITCH FOR CLOCK DELAY MECHANISM Eugene H. Beach, Highland, Mich.

Application August 12, 1952, Serial No. 304,050 Claims. (Cl. 102-16) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon or therefor.

This invention relates to a clock delay mechanism for a mine which is adapted to close a plurality of switches included in the arming circuit of the mine in predetermined time intervals so as to provide a time delay between the laying of a mine and'the arming thereof.

Heretofore, mechanisms have been provided which close circuits within a mine and permit a time lapse between the launching and arming of the mine. It is apparent that the provision of such a device within a mine is essential in order to effectively protect the launching craft. However, the prior art devices were not capable of withstanding the high shock resulting from the impact of the mine and clock mechanism with the water, and accidental closure of the switches and consequent premature arming of the mine were possible. Hence, the necessity arose for developing a time delay mechanism for closing switches in the firing circuitof a mine which could withstand high shocks.

The present invention provides such a mechanism by incorporating a positive means to both retain the switches in the open position prior to actuation of the clockwork and to hold the switches in the closed position after the arming cycle is completed. This is accomplished by means of a locking member rotatably mounted adjacent each switch. Each locking member is spring urged to a position wherein the cam surface provided thereon bears against the contacts of the switch thereby. closing the switch. A cocking plate is centrally rotatably mounted and adapted to be manually operated to simultaneously rotate the locking members to a position wherein fingers integrally formed on these members are disposed between the contacts of the switches thereby providing a positive means for holding the switches in the open position. A rotatable cylinder driven by a conventional clockwork mechanism actuated by a hydrostatically controlled member is provided with a series of slots which coact with followers mounted on the rotatable locking members. When the followers rest against the outer surface of the cylinder, the fingers on the locking members are held I between the contacts and, when the clockwork drives the cylinder to a position wherein the followers drop into the slots, the locking members rotate causing the cam surfaces tliereon to close the contacts of theTswitches. The winding screw of the clock is so located that it is impossible'to wind the clock without first rotating the cooking plate to open the switches. As the clock is wound, the cylinder and dial are rotated and when the desired time delay has been set as determined by the position of the dial with respect to a pointer, the winding key is removed whereupon the cocking plate returns to the original position. However, the switches are retained in'the open position since the cylinder has rotatedto aposition wherein the followers rest against the outer surface thereof.

Three of the four switches provided are'set to be closed at l insulated therefrom.

with the firing circuit within the mine.

2,826,991 Patented Mar. 18,..195

2 3, 2 and 1 minutes prior to the completion of the time delay and the fourth switch closes at the set time. These switches are included in the firing circuit of the mine and thereby the presently disclosed mechanism provides a positive means for delaying the arming of the mine.

A primary object of this invention is the provision of a clock delay mechanism for closing switches in the arming circuit of a mine which mechanism is capable of withstanding the high shock encountered by impact of the mine with the surface of the water.

Another object of this invention is to provide a time delay mechanism to operate switches in the firing circuit of a mine which incorporates positive means for holding the switches in both the open and closed positions thereby effectively preventing premature closing of the switches and insuring operation of the switches after the predetermined period of time has elapsed.

A still further object of this invention is the provision of a clock delay mechanism for'a mine to prevent premature arming thereof in which the timing mechanism cannot be operated when the switches are in the closed position by providing a flange on the cocking plate which must be moved for access to the winding screw.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a plan view of the clock delay mechanism with the cover in place;

Fig. 2 is a plan view of the device with the cover removed;

Fig. 3 is a plan view similar to Fig. 2 with the switches in the open position;

Fig. 4 is a side elevation of Fig. 2 with the casing broken away to show certain details;

Fig. 5 is an elevati-onal view of the cylinder showing the relationship of the slots;

Fig. 6 is a top plan view of the cylinder with the dial and cocking plate removed and with one looking member shown; and,

Fig. 7 is a sectional view along the line 77 of Fig. 6.

Referring now to the drawings wherein like numerals indicate like parts throughout the several views, there is shown at 1 the clock delay mechanism. The cover plate 2 is secured to the body of the device by means of nuts 3 threaded onto bolts 4. The cover plate is provided with a circular window 5 through which the dial 6 and pointer 7 are visible. There is further provided in cover 2 a recessed portion 8 within which is disposed a slot 9 within which is slideably mounted the cocking means for the switches as will be described more fully hereinafter. An aperture 11 is provided in the cover plate through which is passed a cable (not shown) to provide electrical connections from the mine to the switches of the clock mechanism.

In Fig. 2 the cover plate 2 has been removed to show the construction and operation of the switches. Four switches 12 have been provided and, since they are identical in construction, only one will be described in detail. Mounted on a circular plate 13 as by screws 14 is a bracket 15 which provides a support for the switch and operating means therefor. The switch 12 comprises a contact 16 of relatively thick metal and a contact 17 of lighter and more resilient conducting material spaced and The contacts of each switch are provided with leads which connect through a conductor The normal position of resilient contact 17 is out of engagement with contact 16 and these contacts are urged into engagement by a means to be presently disclosed.

Each switch is provided with a locking member 18 to 21 which locking members are substantially identical in construction. Locking member 18 is rotatably mounted on a pin 22, Fig. 4, which-is fixedly mounted on bracket 15. Secured to thisbracket and to the locking member 18 is a spring 23 which serves to urge the locking memher to the position shown in Fig. 2. Locking members 19 to 21 are similarly mounted. Each locking member is provided with a cam surface 24 and a slot 25 which forms a finger portion 26. Upon rotation of the locking members to the position shown in Fig. 3 the contacts 17 extend into slots 25 and the finger portions 26 project between the contacts. It can be seen that in this position the switches are effectively prevented from premature closing due to sudden shock. When the locking memhers are in the position shown in Fig. 2, the cam sur' faces 24 force resilient contacts 17 outwardly into engagement with contacts 16 thereby providing a positive means for retaining the switches in the closed position.

The locking members are rotated and held in the position shown in Fig. 3 by a combination of elements to be now described. Referring to Fig. 4 there is shown a spacing member 27 which is fixedly mounted on the upper surface of locking member 18 and secured to this spacer is a follower 28. It is apparent, therefore, that the follower and locking member will move in unison. Follower 28 is provided with an upstanding cocking pin 29 and counterweight means in the form of upstanding projections 31. It is necessary that each follower act in an individual plane. In order to accomplish this, follower 32 is secured directly to the upper surface of locking member 19 with no spacing member interposed therebetween. Follower 33 is secured directly to the under sur face of locking member 20, and follower 34 is secured beneath locking member 21 with a spacing member (not shown) interposed therebetween. Since the thickness of the spacing members is approximately equal to the thickness of the locking member as seen in Fig. 4, it can be seen that the followers mounted on the locking members 18 to 21 are adapted to operate in individual planes which are spaced apart approximately the width of the locking member. However, it is desired that the cooking pins 29 act in a common plane. Accordingly, in the case of locking members 20 and 21 the cocking pin 29 is mounted on the upper surface of the locking member instead of on the follower.

Mounted in the lowerportion of housing 1 as seen in Fig. 4 is a conventional clockwork mechanism which is actuated by a member 35 in response to water pressure thereagainst. This clockwork drives a cylindrically shaped member 36, Figs. and 6, and dial 6 which is secured to the upper surface of this cylinder as by screws 37. The cylinder 36 is further provided with an upstanding pin 38 which receives a slot 39 in dial 6 and serves as a guide to correctly locate dial 6 with respect to the cylinder. There is provided a boss 41 on cylinder 36 and fitting around this boss is a cocking plate 42 having a central cut out portion and four flanges 43 extending outwardly therefrom. One of these flanges is provided with upstanding pins 44 on the upper ends of which is mounted plate 45 having a knurled knob 46 mounted thereon. This knob extends upwardly through slot 9 in cover plate 2 as shown in Fig. 1. It is apparent that the cocking plate is freely rotatably mounted beneath dial 6 around boss 41 on cylinder 36. A spring 47 fixedly mounted on the underside of a flange 43 and on plate 13 serves to normally retain the cocking plate 42 in the position shown in Fig. 2 in which a flange 43 on the cocking plate abuts a block 48 secured to circular plate 13 by screw 49.

Cylinder 36 is provided with four peripheral grooves or undercut portions 51 in the outersurface thereof each of which is provided with a slot 52 to 55. The relative position and relationship of these slots is shown in Figs.

. 5 and 6. When-the. cylinder and dial are in the position teachings.

shown in Fig. 2, the followers on locking members 18 to 21 are disposed in slots 52 to 55 respectively. When the cylinder and dial are rotated to the position of Fig. 3 and the followers rotated to open the switches, the surface of the cylinder within grooved portions 51 serves to retain the followers in this position.

The winding screw (not shown) for the clockwork is located directly beneath plate 45 on circular plate 13. Hence, in order to wind the mechanism it is first neces sary to rotate the cocking plate by movement of knob 46 within slot 9 in the cover plate. By so doing the flanges 43 on the cocking plate move the followers 28 and 32 to 34 and locking members 18 to 21 to the position of Fig. 3 through engagement with cocking pins 29. As the clock mechanism is wound the cylinder and dial are rotated and the position of the dial with respect to the pointer 7 determines the time delay. It is possible with the presently disclosed apparatus to provide a time delay offrom five to sixty minutes. Upon removal of the winding key the cocking plate is returned to the original position by spring 47. However, the slots 52 to 55 have been rotated out of alignment with the followersand the locking membersare held in the position of Fig. 3 by engagement of the followers with the cylinder After the desired time delay is set on the mechanism the conducting cable (not shown) is plugged into the mine which is then submerged. When the mine reaches a predeter mined depththe hydrostatic pressure responsive mechanism of the mine (not shown) actuates member 35 to release the clockwork which begins to rotate the cylinder 36 and dial 6 to the position of Fig. 2. Slots 52 to 55 are so positioned that none of the switches are closed until three minutes prior to the expiration of the set time delay at which time follower 28 drops into slot 52 to release locking member 18 and to close one switch 12. Locking members 19 to 21 are sequentially released at one minute intervals so that upon the expiration of the time delay the mine is armed.

It can be seen that there has been provided a device which enables the mine laying ship to leave the area prior to the time of arming of the mine. The presently disclosed clock delay mechanism provides a positive means for both'holding the switches in the open position and for locking the switches in the closed position. It can be seen from Fig. 3 that fingers 26 of the locking members are interposed between contacts 16 and 17 when the switches are in the open position and that no shock irrespective of its force will be able to close the switches. On the other hand, when the cam surfaces 24 of the locking members urge contacts 17 into engagement with contacts 16 to close the switches when the device arms the mine, no shock can dislodge the contacts from this position.

Obviously many modifications and variations of'the present invention are possible in the light of the above For example, while four switches havebeen shown as actuated by the clock delay mechanism, the specific number of switches provided could be varied to suit any operational requirement. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifithe same, a clockwork mechanism, means driven by said clockwork mechanism for holding the cam in a position wherein the locking means thereof engages the contacts open positionwhereby upon actuation of said clockwork said last named means releases said cam to close said switch means.

2. A clock delay mechanism comprising a plurality of switches having contacts normally in the open position, a plurality of rotatable locking means equal in number to the number of said switches and disposed adjacent each switch respectively, each of said locking means being rotatable about a different axis thereby to positively open and close the contacts of each switch, a clockwork mechanism, a cylinder rotatable about the axis thereof and driven by said clockwork and having a plurality of cam surfaces thereon, cam follower means mounted on each locking means and cooperating with individual ones of said plurality of cam surfaces of said cylinder in one position thereof to retain said locking means in a position to engage and open said switches, and means urging said locking means to a switch closing position whereby upon actuation of said clockwork the cylinder is driven to a position releasing said follower means to permit said locking means to rotate to a switch closing position in predetermined time delayed relation, the axes of each of said locking means being parallel to each other and to the axis of said cylinder.

3. A clock mechanism comprising a plurality of switches provided with contact members, a plurality of locking members each having a cam surface and finger integral therewith rotatably mounted on different axes adjacent each switch, a spring urging each locking member to a position wherein the cam surface thereof bears against the contact members of said switches to close the same, a clockwork mechanism, a cylinder driven about the axis thereof by said clockwork mechanism and having a plurality of cam surfaces thereon, and means mounted on each locking member and adapted to cooperate with an individual one of the cam surfaces of said cylinder to retain said locking members in a position wherein the fingers thereof project between said contact members to open the switches whereby upon actuation of the clockwork the cylinder is rotated to a position releasing said locking members for rotation to a switch closing position in predetermined time delayed successive order.

4. A clock mechanism for delaying the arming of a mine comprising a switch having a fixed contact and a resilient contact normally in an open position, a locking member having a cam surface and finger integral therewith rotatably mounted adjacent said switch, spring means urging saidlocking member to a position wherein the cam surface thereof bears against the resilient contact to urge the same into engagement with the fixed contact, -a clockwork mechanism, a cylinder having a slot therein and driven by said clockwork mechanism, and a follower fixedly mounted on said locking member and engaging the outer surface of said cylinder thereby pivoting the locking member to a position wherein the finger thereon projects between the contacts of said switch whereby upon actuation of said clockwork said cylinder is rotated to a position wherein the follower drops into theslot in said cylinder and the locking member rotates to a switch closing position in predetermined time delayed relation.

5. In a device of the class described for delaying the arming of a mine comprising, in combination, a switch provided with a stationary contact and a resilient contact normally in the open position adapted to be connected in the firing circuit of a mine, a locking member rotatably mounted adjacent said switch and having a cam surface and finger portion integral therewith, spring means urging the cam surface of said locking member into engagement with the resilient contact thereby providing a positive means for locking the switch in the closed position, means for rotating and retaining said locking member in a position wherein the finger thereof projects between said contacts thereby elfectively preventing the closing of said switch due to shock, and means for releasing said locking member to close said switch in predetermined time delayed relation.

References Cited in the file of this patent UNITED STATES PATENTS 2,219,589 Flegel Oct. 29, 1940 2,642,801 Gleason June 23, 1953 2,713,308 Brown July 19, 1955 

